The disclosed embodiments of the present invention relate to an audio signal processing apparatus and an audio signal processing method, and more particularly, to an audio signal processing apparatus and an audio signal processing method that can generate an optimal audio output for multimedia devices including a VCD player, a DVD player and a BD player, etc.
Please refer to FIG. 1. FIG. 1 is a simplified block diagram illustrating a conventional audio signal processing apparatus 100 applied to a BD player. As shown in FIG. 1, the audio signal processing apparatus 100 comprises: an HDMI audio interface 102, an analog audio interface 104, a first downmixing unit 106, a second downmixing unit 108, and a decoding unit 110. The decoding unit 110 is utilized for decoding an input audio signal Si to generate a first output audio signal S1 with a first number of audio channels. The first downmixing unit 106 is utilized for downmixing the first output audio signal S1 according to an audio channel configuration of the HDMI audio interface 102 to generate a second output audio signal S2 with a second number of audio channels for the HDMI audio interface 102. The second downmixing unit 108 is utilized for downmixing the first output audio signal S1 according to an audio channel configuration of the analog audio interface 104 to generate a third output audio signal S3 with a third number of audio channels for the analog audio interface 104.
However, for example, if the first output audio signal S1 has 5 audio channels (such as a center audio channel, a main left audio channel, a main right audio channel, a left surround audio channel, and a right surround audio channel), and the second output audio signal S2 only has 2 audio channels (such as a main left audio channel and a main right audio channel) due to the audio channel configuration of the HDMI audio interface 102 is a main left audio channel and a main right audio channel, and the third output audio signal S3 also only has 2 audio channels (such as a main left audio channel and a main right audio channel) due to the audio channel configuration of the analog audio interface 104 is a main left audio channel and a main right audio channel, then the audio signal processing apparatus 100 only can provide two output audio signals S2, S3 of 2 audio channels when the audio signal processing apparatus 100 receives the input audio signal Si having 5 audio channels. In other words, the audio signal processing apparatus 100 only can provide two output audio signals S2, S3 with a main left audio channel and a main right audio channel even the audio signal processing apparatus 100 receives the input audio signal Si having a center audio channel, a main left audio channel, a main right audio channel, a left surround audio channel, and a right surround audio channel. In this way, if the audio signal processing apparatus 100 is coupled to four speakers via the HDMI audio interface 102 and the analog audio interface 104, the four speakers only can output sounds of a main left audio channel and a main right audio channel.